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United States Patent |
5,289,786
|
Clay
|
March 1, 1994
|
Tri-generation garbage incinerator
Abstract
The present invention includes four chambers for containing refuse, a
porous membrane at least partially enclosing the chambers, and a housing
enclosing the porous membrane and the chambers. Combustion fuel is
supplied to the porous membrane so that surface combustion takes place at
the surface of the porous membrane facing the chamber for burning the
refuse contained in the chamber. Electrical means may also be employed to
provide combustion of the refuse. Safety features include pressure
feed-back means for monitoring and regulating the pressure within the
apparatus and temperature feed-back means for monitoring and regulating
the temperature within the apparatus. A particle bin is positioned below
the chamber for receiving burned particles from the chamber. The gases
generated from the burning refuse is collected and pumped through a super
heating and purifying chamber (eliminated all hazardous affluent) and into
the boiler type heat exchanger and thereby producing steam for electrical
generation. The electricity produced is then partially used to run a
cryogenic plant which produces liquid oxygen which is used to produce
oxygen gas, the major fuel component, used to produce the surface
combustion used in the incinerator. Therefore a tri-generation system is
generated which reduces operating cost, increase operating efficiency of
the incinerator and the bi-produce sold to others generate an off-setting
income.
Inventors:
|
Clay; Haile S. (P.O. Box 326, LaHonda, CA 94020)
|
Appl. No.:
|
009176 |
Filed:
|
January 26, 1993 |
Current U.S. Class: |
110/233; 110/234; 110/346; 122/2 |
Intern'l Class: |
F23B 007/00 |
Field of Search: |
110/233,234,346
122/1 R,2
|
References Cited
U.S. Patent Documents
5134944 | Aug., 1992 | Keller et al. | 110/234.
|
5199356 | Apr., 1993 | Hoffert | 110/233.
|
Primary Examiner: Favors; Edward G.
Attorney, Agent or Firm: Ware & Freidenrich
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation-in-part of patent application
Ser. No. 07/829,421, filed Feb. 3, 1992 Pat. No. 5,191,846.
Claims
In the claims:
1. A tri-generation garbage incinerator, comprising:
an incinerator apparatus for burning refuse wherein said incinerator
apparatus uses oxygen and a fuel to support the burning of refuse and
wherein the burning of refuse in said incinerator apparatus generates
heat;
fuel means for supplying fuel to said incarcerator apparatus wherein said
fuel includes oxygen;
steam generation means in communication with said incinerator apparatus and
including a liquid supply for generating steam from using heat generated
in said incinerator apparatus by the burning of refuse;
power means for generating electricity, such using the steam generated by
said steam generation means;
liquid oxygen generation means, powered by the electricity generated by
said power means, for generating liquid oxygen; and
transferring means for transferring liquid oxygen generated by said liquid
oxygen generation means to said fuel means for use in said incinerator
apparatus.
2. An apparatus as recited in claim 1 wherein said liquid oxygen generation
means is a cryogenic plant.
3. An apparatus as recited in claim 2, wherein said cryogenic plant further
generates liquid nitrogen.
4. An apparatus as recited in claim 1 wherein said incinerator apparatus
for burning refuse, comprises;
a chamber for containing refuse;
a porous membrane at least partially enclosing said chamber;
a housing enclosing said porous membrane and said chamber;
fuel means for supplying fuel to said porous membrane wherein said fuel
includes oxygen; and
surface combustion means at the surface of said porous membrane facing said
chamber for burning refuse contained in said chamber by surface
combustion.
5. An apparatus as recited in claim 1 wherein said steam generation means
is a boiler-type steam generator.
6. A self-contained garbage incinerating system, comprising:
a chamber for containing refuse;
a porous membrane at least partially enclosing said chamber;
a housing enclosing said porous membrane and said chamber;
fuel means for supplying fuel to said porous membrane;
surface combustion means at the surface of said porous membrane facing said
chamber for burning refuse contained in said chamber by surface
combustion;
steam generation means including a fluid source and in communication with
said surface combustion means for generating steam; and
electricity-generating means which receives steam generated by said steam
generation means, for generating electricity therefrom.
7. A self-contained garbage incinerator as recited in claim 6, further
comprising:
liquid oxygen generation means, powered by the electricity generated by
said electricity-generating means, for generating liquid oxygen; and
transferring means for transferring liquid oxygen generated by said liquid
oxygen generation means to said fuel means for supplying fuel to said
porous membrane.
8. A garbage incinerating system, comprising:
(a) a surface combustion garbage incinerating apparatus, including;
a chamber for containing refuse;
a porous membrane at least partially enclosing said chamber;
a housing enclosing said porous membrane and said chamber;
fuel means for supplying fuel to said porous membrane;
surface combustion means at the surface of said porous membrane facing said
chamber for burning refuse contained in said chamber by surface
combustion; and
(b) a cryogenic apparatus in communication with said surface combustion
garbage incinerating system wherein said cryogenic apparatus generates
liquid oxygen; and
(c) transferring means for transferring liquid oxygen generated by said
cryogenic plant to said fuel means for use in said self-contained
incinerator apparatus.
9. A surface combustion garbage incinerating apparatus as recited in claim
8 further comprising:
(d) steam generation means in communication with said surface combustion
garbage incinerating apparatus and including a liquid supply for
generating steam from using heat generated in said incinerating apparatus
by the burning of refuse;
(e) power means for generating electricity, such using the steam generated
by said steam generation means.
10. A surface combustion garbage incinerating apparatus as recited in claim
9 wherein said cryogenic apparatus is powered by the electricity generated
by said power means.
11. A tri-generation garbage incineration method, comprising the steps of:
burning refuse in an incinerator apparatus which uses oxygen and a fuel to
support the burning of refuse and wherein the burning of refuse in said
incinerator apparatus generates heat;
supplying fuel to said incinerator apparatus wherein said fuel includes
oxygen;
generating steam in a steam generating apparatus which is in communication
with said incinerator apparatus and which includes a liquid supply for
generating steam by using heat generated in said incinerator apparatus by
the burning of refuse;
generating electricity by using the steam generated by said steam
generation means;
generating liquid oxygen in an cryogenic apparatus powered by the
electricity generated in said generating electricity step; and
transferring liquid oxygen generated by said liquid oxygen generating step
for use in said incinerator apparatus.
Description
FIELD OF THE INVENTION
The present invention relates to an incinerator apparatus. More
specifically, it relates to a self-contained incinerator and method for
burning refuse in an industrial, municipal or household environment, the
production of electricity, and the production of liquified gases.
BACKGROUND OF THE INVENTION
For many years, residents and municipalities burned their own refuse in
incinerators which did not have air pollution reducing devices
incorporated therein. Most local and state governments have outlawed
residential burning activities due to the air pollution problems created
by the burning. Instead of burning, residents now send their waste to
landfills. However, currently, landfills are being filled to capacity and
new landfill sites are becoming less available.
In an effort to solve the landfill problems, communities are turning to
recycling and municipal incineration to dispose of refuse. However, these
solutions are still in the formative stages and therefore do not provide
immediate relief from the ongoing problems of waste management. The
current solutions do not solve the air pollution problems associated with
burning garbage, and operate at considerable low efficiency. Current
incinerators require the constant input of outside air to sustain the
burning process. Air is approximately 76% nitrogen which does not burn.
The nitrogen, however, must be heated and constantly discharged into the
atmosphere. The discharged nitrogen absorbs as much as 70% of heat
generated by the burning refuse, and it picks up and carries fly ash which
must be removed before the discharge into the atmosphere.
Until the pollution and efficiency problems associated with municipal,
industrial and household incineration are solved, other methods are needed
to relieve the landfill problems. Accordingly, there is a need for a new
type of incinerator and an incineration system. Furthermore, there is a
need for an incineration system which operates in a closed cycle
environment, is fuel efficient, and is safe for municipal use and other
uses.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to provide an
improved and safe municipal, industrial and household incinerator
apparatus.
It is another object of the present invention to provide a refuse burning
apparatus and method which burns refuse without releasing air polluting
contaminants into the ambient environment.
It is a still another object to provide an incinerator with a short, closed
cycle process.
It is a yet a further object of the present invention to provide an
incinerator which is self cleaning.
It is yet another object to provide an incinerator which is compact, and
has no emission stack.
In accordance with these and other objects, the present invention includes
a chamber for containing refuse, a porous membrane at least partially
enclosing the chamber, and a silo-type housing enclosing the porous
membrane and the chamber. Combustion fuel is supplies to the porous
membrane so that surface combustion takes place at the surface of the
porous membrane facing the chamber for burning the refuse contained in the
chamber. Safety features include pressure feed-back means for monitoring
and regulating the pressure within the apparatus and temperature feed-back
means for monitoring and regulating the temperature within the apparatus.
A particle bin is positioned below the chamber for receiving burned
particles from the chamber.
The present invention also recycles this waste heat through an after-burner
which purifies the gases of hazardous particles, and adds additional heat
before it is introduced to the heat recovery process. Steam is generated
using the heat and electricity produced therefrom. The electricity is then
used to power a cryogenic plant which produces liquified oxygen and
nitrogen. The oxygen in turn is used to fuel the incinerator. It is
expected that the waste heat recovery increases by 300 to 400%, thus
greatly enhancing the generation of electrical power as a by-product.
The incinerator of the present invention does not use outside air to
sustain the burning process. Hence, the heat that was previously lost in
incinerators of the prior art is now contained within the incinerator and
is absorbed by the gases generated from the burning refuse. Therefore, the
affluent gases carry a higher heat value, which give rise to a greater
recovery of waste heat in the form of steam or power.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, and many of the intended advantages of the present
invention, will be readily appreciated as the same becomes better
understood by reference to the following detailed description when
considered in connection with the accompanying drawings wherein:
FIG. 1A is a cross-sectional top view of the present invention;
FIG. 1B is a cross-sectional top view taken along cross-section B--B of
FIG. 1D;
FIG. 1C is a side cross-sectional view taken along view A--A of FIG. 1D;
FIG. 1D is an exterior view of the combustion apparatus of the present
invention;
FIG. 2 is a schematic diagram of the tri-generation system of the present
invention;
FIG. 3 is a graph of the temperature verse time showing the burn cycle of
the refuse and the temperature cycle of the chamber;
FIG. 4 is a cross-sectional view of one chamber or silo showing its control
systems; and
FIG. 5 shows a top view of a single chamber of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the
invention, examples of which are illustrated in the accompanying drawings.
While the invention will be described in conjunction with the preferred
embodiments, it will be understood that they are not intended to limit the
invention to those embodiments. On the contrary, the invention is intended
to cover alternatives, modifications and equivalents which may be included
within the spirit and scope of the invention as defined by the claims.
Attention is drawn to FIGS. 1A-1D, 2 and 4 which show views of the present
invention which operates utilizing the process known as surface
combustion. FIGS. 1A-1C show four surface combustion incinerators as part
of a large incinerator without some of the detail shown in FIG. 4 which
shows just one chamber. The present invention can be utilized with one or
more incinerator chambers, depending on the specific design details
incorporated therein. Moreover, a household incinerator apparatus can
include just the surface-combustion incinerator portion of this invention.
For example, a configuration like that shown in FIG. 4 can be used as a
household single-generation apparatus.
As shown in FIG. 1A, one embodiment includes four chambers 11 for holding
refuse and a porous membrane 13 which is separated by a coaxial air space
14 from the chamber 11. The chambers are supported by supports (not shown)
so that around the chamber 11, a uniform coaxial air space 14 is
maintained. The porous membrane 13 acts as a combustion wall and a
radiating surface facing inwardly to the chamber 11. The membrane is
constructed from porous refractory material such as graphite, which is
also a neutral refractory material. The porous membrane 13 discharges the
fuel supplied from the fuel supply 20, so that combustion occurs at the
inner surface of porous membrane 13, burning the refuse contained in the
chambers 11.
In the first embodiment, combustion gases are used to produce a radiant
heat source. If, however, the radiant heat source was produced by
electrical means, such alteration would fall within the scope of the
present invention. Electrical means such as glowing tubes may replace
membrane 13.
Fuel supply 20 is a mixture of industrial oxygen, stored in container 23,
and methane, stored in container 35, which is combined at mixing valve 22
(see FIG. 2). Such fuels are obtainable in pressurized containers for easy
installation on the apparatus of the present invention. Other equally
combustible combinations of fuel, such as propane, acetylene, butane or
hydrogen, can be combined to effect the surface combustion at the porous
membrane described herein.
Surface combustion is an explosive mixture of gas and air in the proper
proportions for complete combustion and which is caused to burn without
flame in contact with a granular incandescent surface, in this case,
porous membrane 13. A large portion of the potential energy of the fuel is
immediately converted into radiant heat form so that accelerated
combustion is concentrated at surface 13. As the surface combustion
becomes incandescent, it will produce intense radiation heat that will
cause the refuse which is in close proximity to spontaneously combust.
Moreover, a reflecting surface may be included on the surface 10 of the
porous membrane 13 facing chamber 11.
Surface combustion provides the attainment of very high temperatures and
rapid heating. The proportions of methane and oxygen (purified air which
is approximately 99% oxygen) as a fuel used to effect surface combustion
per one hundred pounds of compacted refuse are oxygen by volume 67% and
methane by volume 22%, a ratio of approximately 2 to 1. Were non-purified
air to be used in place of purified air, the ratio of air to burn gas
would be approximately 10 to 1. The effective temperature of the refuse is
maintained between 1500.degree. to 1700.degree. Fahrenheit.
The surface combustion is supported by the oxygen admitted with the burn
gases of fuel supply 20 and is not influenced by the oxygen and other
gases that surround the refuse. Because the refuse is burned primarily
from radiation heat generated at the porous membrane 13, no combustion air
is required to sustain the burning of the refuse. Accordingly, there is no
need to supply additional oxygen in the form of air received from the
ambient environment to fuel the combustion. The fuel supplied to the
porous membrane 13 by fuel supply 20 is sufficient to effect the desired
surface combustion. An electronic ignition source or laser may be used to
start the combustion.
Chamber 11 houses refuse which is slated for incineration. As the surface
combustion generates radiant heat that is transferred from the porous
membrane 13 across space 14, intense heat is concentrated at the chamber
11. Since the surface combustion becomes incandescent instantaneously, the
complete burn cycle of the incinerator is finished within a short time.
The incineration of all of the refuse within the silo 1 is fast and
complete. Due to the intense heat and speed of the incineration, gases
produced from the refuse during the incineration process are completely
burned, therefore, there are no air contaminants left in the system to
release to the ambient environment, thus providing a pollution free
incineration apparatus. Accordingly, there is no requirement for a flue or
emission stack to exhaust unburned nitrogen and related flue type
discharges.
FIG. 2 shows the incinerator portion of the present invention in
combination with the electricity generator portion and cryogenic plant
portion. Steam from the incinerator is used to produce electricity which
is, in turn, used to run the cryogenic plant. As shown in FIG. 2, a
portion of the electricity produced at conventional electricity-generating
plant 24 is used to run a conventional cryogenic plant 28 which produces
from ambient air received at intake 27 liquid nitrogen transferred by pipe
31 and stored in container 30, and liquid oxygen transferred in pipe 31
and stored in container 29. The liquid nitrogen produced is sold to
others. The boil-off from liquid oxygen stored in container 29 is stored
as O.sub.2 gas in container 23. The oxygen gas is then mixed with burn gas
stored in container 35 at mixing valve 22. The electricity-generating
plant 24 (discussed below) which receives steam generated from refuse
burning in incinerator 18, is the second leg of the tri-generation system
as shown in FIG. 2. The cryogenic plant 28 represents the third leg of the
tri-generation system of the present invention. By its inclusion, the fuel
cost for the combustion surface burn is lowered.
Returning to FIG. 1C, in order to supply energy to the electricity
generator plant 24, the waste heat, i.e., steam and gases generated by the
burning refuse is collected at chamber 4 and pumped by pump 16, through
super heat chamber 15 where it is super heated, purified, forced through
the steam generator 6, and returned to chamber 4. Steam generator 6 is a
boiler-type heat exchanger and thereby produces steam for electrical
generation.
The steam and gas cycle in the embodiment shown in FIG. 1C, more
specifically, provides that the steam and gases stored in chamber 4 is
transferred through pipe 8 and pumped by pump 16, through chamber 15 back
through steam generator 6 and returned to chamber 4 through pipe 7.
Chamber 15 is heated by combustion surface burn at surface 22 contained in
container 2. The combustion at combustion surface 22 can be supported by
the same gas as is combustion at surface 10, or can be supported by, for
example, electrical means. Combustion surface 22 is housed co-axial to
container 2 and is separated from porous membrane 13 by space 19. The
steam generated is stored in chamber 12, and then the steam is transferred
through pipe 12 and is used to produce the electricity at
electricity-generating plant 24. Electricity passes through power transfer
means 26 and is used to operate the cryogenic plant 24. The surplus power
sold to market through electricity-transfer means 25. This inclusion of
the power plant 24 also reduces the cost of operating the incinerator.
The controls for the three legs of the tri-generation incinerator are shown
in FIG. 2. They include incinerator controls 32, electric power plant
controls 33, and cryogenic plant controls 34.
The incinerator position of the present invention is shown as two different
embodiments in FIGS. 1A-1D and FIG. 4. Other suitable configurations are
within the scope of this invention. Generally, the components of the
incinerator portion should be suitable for use at very high temperatures.
Chamber 11 consists of a wire cylinder, rectangle or other suitable
configuration which is enclosed at the bottom 21 and top 21'. The wire is
preferably of the type which has a minimum chemical interaction with
refuse and the burn gases. Furthermore, the wire must be strong enough to
sustain impacts from exploding items of the refuse such as used spray
cans. A suitable type of wire is, for example, titanium, or stainless
steel. Alternatively, chamber 11 could be made from high temperature and
high strength glass.
The chamber 11 surrounded by porous membrane 13 is positioned within an
air-tight housing 18 which is sealed during the combustion and cool down
periods to prevent any escape of gasses and burning particulates. A strong
material which is able to withstand the temperatures and pressures
generated from within the apparatus and which is inert to the refuse and
gases produced from the incineration is preferable. Housing 18 is
therefore preferably constructed from, for example, stainless steel. The
housing 18 is also insulated by insulation 18' to prevent heat from
escaping into the ambient environment.
The housing 18 surrounds the back-pressure chamber 18" (see FIG. 4) which
forces the mixture of fuels through the porous membrane 12 to sustain the
surface combustion. Back-pressure chamber 18" is coaxial to porous
membrane 13 to achieve uniformity of the surface combustion. Upon closure
of silo lids 1 and cleanout plug 17, the housing 18 becomes a pressure
tank and therefore silo lid 1 and clean-out plug 17 are also constructed
to adequately endure the temperatures and pressures from within the
apparatus.
Feed-back systems monitor and regulate the operating parameters of the
apparatus. Pressure feed-back means and temperature feed-back means are
provided by a conventional monitoring and feed-back system 32. The
pressure feed-back system monitors pressure through monitor 32' and the
temperature feed-back system monitors the temperature through monitor 32".
The pressure is controlled by varying temperature and by releasing
pressure through pressure release value 5. Release valve 5 is shielded by
a filter 5' that removes contaminants from the passing gas. Charcoal would
be a typical filtering material for this purpose.
The temperature is controlled by adjusting the fuel supply 20. The
feed-back system 32 is equipped with an automatic shut-down mechanism in
the event that the pressure or temperature exceed safety limitation
threshold values. Furthermore, the feed-back system also monitors the seal
of the lid 1 operated by a hinge 1' and at the plug 17.
The refuse which is placed in chamber 11 is preferably compacted by a trash
compactor. Each chamber 11 may hold up to tons of refuse. The refuse may
be introduced into the chamber 11 in a bag so that debris is not forced
through the wire mesh prior to combustion. Were the present invention to
be used by a household incinerator, it could hold 100 pounds of refuse and
therefore approximately four times the volume of the average household
trash compactor. When used as a household incinerator, the present
invention is compact, having dimensions nearly equivalent to those of a
household trash compactor. Since refuse varies in composition, a humidity
monitor 34 and regulator is also provided to sustain a humidity level of
between 0-1% in the radiant heat transfer zone to assure a complete burn
of the enclosed refuse.
FIG. 3 depicts expected temperature verse time curves of the refuse
(indicated by the solid line) and the chamber 22 (indicated by the dotted
line). The burn cycle of the present invention is summarized as follows.
The combustion surface is ignited so that the radiant heat is
instantaneously transferred to the refuse. In the first moments of the
refuse being subjected to the intense radiant heat emanating from the
porous membrane, the moisture embodied in the refuse is driven off as
steam. The steam rises to the top of the interior of the apparatus where
it is condensed and channeled to the bottom of the incinerator (not
shown). The dried refuse is burned to ashes as a consequence of the
intense heat radiating from the porous membrane 13. As shown in FIG. 3,
the burn cycle is completed with minutes.
As further shown in FIG. 3, the ambient temperature within housing 18 is
considerably below the refuse burn temperature due to the directness of
radiant heat, the condensing steam and water collected in the base of the
unit. The cool down period may take more than an hour to return the system
back to room temperature.
The near spontaneous combustion of the refuse in chamber 11 eliminates the
need to stir or agitate the refuse to sustain its burning. As the garbage
is burned, its ashes fall by the force of gravity to the incinerator
floor. Also, means for providing sonic vibrations such as vibrator 36 is
provided to force ashes off the core of unburned refuse to expose it
directly to the surface combustion at the porous membrane's 13 interior
surface. Therefore, the core of the refuse is continually exposed to the
radiant heat at the surface of the porous membrane 13, thereby
accelerating the complete burning of the column of refuse.
The bottom 21 of the chamber 11 is replaceable in the event that it becomes
clogged by molten glass, plastics and metals which resolidify during the
cool-down phase. The matter which does pass through bottom 21 of chamber
11 travels through collection space 9, the ash space 10, and ultimately
exits the apparatus through cleanout 17. The residual refuse that fall
through the chamber 11 is collected in space 9 and burned on a high
temperature glass shield 41 which protects combustion surface 13 but is
transparent to the radiation heat from combustion surface 42 below. The
burned refuse then falls through to ash space 9'.
While the disclosure herein has been directed toward describing an
incinerating apparatus for use in a municipal environment, the present
invention is equally applicable to industrial and household environments
(with possibly some sealing-down modifications). The dimensions of the
apparatus for use in an industrial environment may be enlarged, however,
the same principles as described herein are applicable to commercial
incinerators as well.
Clearly, the general object of the present invention to provide an improved
municipal household or industrial incinerator apparatus has been met.
Also, the object of the present invention to provide refuse burning
apparatus and method for burning which burns refuse without releasing air
polluting contaminants into the ambient environment has been met. The
household model may also be portable.
Moreover, the object to provide an incineration apparatus safe for
municipal use has been met as has the object to provide an incinerator
with a short, closed cycle process. Furthermore, the object of the present
invention to an incinerator which is self cleaning has also been met.
Finally, the object to provide an incinerator which is compact, and has no
emission stack has also been met.
While the present invention has been shown and described in what is
presently conceived to be the most practical and preferred embodiment of
the invention, it will become apparent to those of ordinary skill in the
art that many modifications thereof may be made within the scope of the
invention, which scope is to be accorded the broadest interpretation of
the claims so as to encompass all equivalent structures.
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